EPIC nuts/studs loosening thread (reposting stupid stuff without reading = warning)
#283
You might have trouble getting studs much bigger than that on there - as I said, I had to grind the housing just to get the nuts on.
Good locking nuts are likely more important than locking washers. There's always the bent-tab style (along with wires), the idea being to keep things from spinning. Then even if they stretch, the worst you have is a bit of a leak. But it's a lot harder to stretch the bigger studs.
Good locking nuts are likely more important than locking washers. There's always the bent-tab style (along with wires), the idea being to keep things from spinning. Then even if they stretch, the worst you have is a bit of a leak. But it's a lot harder to stretch the bigger studs.
#284
Do you run a gasket between mani and turbo, Splitime?
This is probably completely misguided, and I'll probably be proven wrong in short order, but I just thought of a little theory that I'll run by you engineer types.
So, people say that it's not just vibration which loosens nuts, but also the thermal expansion of the metal. So, in a gasketless connection, there is nothing to compress so the metal simply grows and pushes the nut loose. With a gasket, there's something to compress and the nuts stay put.
Be gentle guys.
This is probably completely misguided, and I'll probably be proven wrong in short order, but I just thought of a little theory that I'll run by you engineer types.
So, people say that it's not just vibration which loosens nuts, but also the thermal expansion of the metal. So, in a gasketless connection, there is nothing to compress so the metal simply grows and pushes the nut loose. With a gasket, there's something to compress and the nuts stay put.
Be gentle guys.
All it takes is the cast iron expanding beyond the yield point of the bolt, and it reduces the clamping preload. That's why you have to chase the torque multiple times. The stud is continually stretching. Someone should accurately measure the length of each stud to a thou or half a thou before installing it, then take it out and measure after chasing the torque a couple times. Bet it stretched.
#287
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How do OEMs keep their studs and/or nuts from falling off?
There's millions of factory turbo'd vehicles that aren't experiencing BS like this.
I think you guys are trying to hard. Is there any way we can get data on OEM R&D department proven solutions?
There's millions of factory turbo'd vehicles that aren't experiencing BS like this.
I think you guys are trying to hard. Is there any way we can get data on OEM R&D department proven solutions?
#288
Even the Mazdaspeed has the turbo a little further away while there are so many good reasons we think it should be on top like Begi and FM does...
Just trying to think differently.
#291
Yeah, OEM stuff isn't much tracked. :-)
That's a general issue in the miata world. Makes sense since he's right more often than most. But taking anyone's word as gospel is ridiculous.
Here's the thing: Don't stretch the bolt beyond it's yield point. Why do you think larger studs help? Because to hold on what you need to hold on, just put a small torque on the bolt and leave it. That's the answer to the heat cycling. :-)
Part of the reason to keep them short is to keep the heat in - if you made them longer, you'd still want to do what you can to keep the heat in, and then you'd have your same issues back. Why waste the energy leaking heat out?
Then again, you get much more from good flow than not. Long manis tend to crack often, so really, cast is better anyway. :-)
All it takes is the cast iron expanding beyond the yield point of the bolt, and it reduces the clamping preload. That's why you have to chase the torque multiple times. The stud is continually stretching. Someone should accurately measure the length of each stud to a thou or half a thou before installing it, then take it out and measure after chasing the torque a couple times. Bet it stretched.
OEM turbo manifold are usually longer and the junction between the manifold and turbo is firther away from the head and does not heat like a **** as in a miata. Talons, SRT4, and others have a little more runner length. Most aftermarket kits for Hondas have more runner length too.
Then again, you get much more from good flow than not. Long manis tend to crack often, so really, cast is better anyway. :-)
#292
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I discovered inconel turbo gaskets today. Too bad they're only in Supra sizes:
Twins Turbo Motorsports, Inc. - Inconell T-6 Turbo Gasket
Yes, the turbine housing has an inconel heat shield around it too.
Twins Turbo Motorsports, Inc. - Inconell T-6 Turbo Gasket
Yes, the turbine housing has an inconel heat shield around it too.
#294
I was looking at the wide selection of "locking nuts" on mcmasters website
would anyone recommend any of these?
McMaster-Carr
would anyone recommend any of these?
McMaster-Carr
#295
I was looking at the wide selection of "locking nuts" on mcmasters website
would anyone recommend any of these?
McMaster-Carr
would anyone recommend any of these?
McMaster-Carr
Nut Type Locknuts
Locknut Type Distorted-Thread
Distorted-Thread Style Oval Lock with Flange
I'd choose them in M10x1.5 for the turbo.
#296
Tour de Franzia
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I was looking at the wide selection of "locking nuts" on mcmasters website
would anyone recommend any of these?
McMaster-Carr
would anyone recommend any of these?
McMaster-Carr
#298
Update: 304 studs and 15mm head flange nuts*. Track day at Spa Francorchamps: studs look fine, better than ever before, but 2 nuts spun off completely and I was making 0.2bar after a number of laps. Should have used Resbond on them or copper coated nuts.
*) This kind:
*) This kind:
You can see stud #3 has the threads flat from where the turbo hung when the nut flew off.
Before, they wouldn't come out and nuts would hardly move. Going to do new studs, and Resbond the hell out of every thread.
I've now got the car to a point where I can remove the turbo without removing or even loosen the manifold. Yay!
#300
My friend's Supra turbo uses gaskets between the turbine flange and the manifold flange... OEM. He beats the **** out of it and hit the dyno the other day, never has any problem w/ loosening nuts/studs. Granted, no trackdays yet, but as far as I know other turbo supras don't run into this problem either.
What if the OEM gaskets (copper?) are there to absorb the heat and expand, and since you guys aren't running them/any, the next quickest means of heat absorption is the studs/nuts.
What if the OEM gaskets (copper?) are there to absorb the heat and expand, and since you guys aren't running them/any, the next quickest means of heat absorption is the studs/nuts.